fix: resolve CI linting failures in test files

tests/unit/test_models.py

@@ -1,8 +1,14 @@
-"""Tests for docgen models."""
-
-import pytest
 from pathlib import Path
-from docgen.models import Endpoint, Parameter, Response, HTTPMethod, DocConfig, OutputFormat, ParameterIn
+
+from docgen.models import (
+    DocConfig,
+    Endpoint,
+    HTTPMethod,
+    OutputFormat,
+    Parameter,
+    ParameterIn,
+    Response,
+)
 
 
 class TestEndpoint: